Hi,
My 08 WRX has failed its MOT today due to high C02 emissions, I suspect it may be a faulty MAFF sensor, but also doesn't run as smoothly as I'd like at idle, just wondering if anyone has any ideas on what I should do to rectify the problem, or know of any good garages in the south west wales area that may be able to help me?

Thanks guys

 

as mafs are pricy try swapping it with another first , maybe a used one on ebay if it’s cheap enough or borrow someone’s , any leaks on the exhaust system , plus are 02 sensors ok ? have you tried a code reader as it will tell you a bit of 02 sensor information ,a basic code reader is about 15 to 20£ on ebay

 

Has it been decatted?

 

No its completely bog standard at the moment

 

Did you try the 'Italian tune-up' for about 10 mins, then get the car immediately into the emissions testing equipment?

 

Unfortunately the emissions test was the last thing they did 🙈. It also failed with spectacular fashion being twice over the limit.